The present invention relates to systems and methods utilizing inputs and outputs for purposes of controlling equipment (e.g., semiconductor process equipment), industrial machinery, processing lines and the like, and more particularly to input and output control systems and methods utilizing distributed input/output modules and integral interlocks.
A variety of control systems for equipment, processing lines, assembly lines and the like have been proposed and utilized to varying degrees. For example, systems based on the use of digital computers and/or microprocessors/microcontrollers are known to provide a reasonably high degree of programmable input/output control for such applications. While the advances in this general field have been relatively great, due to reasons such as safety and conventional design practices, there are a number of undesirable attributes of such conventional control systems.
FIG. 1 illustrates an exemplary control system such as might be found in a piece of processing equipment, such as for fabricating semiconductors. Controller 10 serves to provide control to the equipment by way of interface 16 (which may be a series of wires, etc.) coupled to control terminals of relays distributed through the equipment, and may also receive inputs from sensors in the equipment. Signals to and from the relays and sensors are coupled to controller 10, thereby providing a highly centralized control system for the equipment. In certain of such systems, the connections to the relays and/or sensors are made by way of what are frequently referred to as VME cards 14, which may be added to controller 10 in the desired number and type in order to satisfy the input/output control requirements for the equipment. Controller 10 may be coupled to another computer via interface 12. The inputs and outputs from controller 10 may, in general, be either inputs or outputs, digital or analog, etc.
Such conventional systems, while providing a highly centralized form of control, suffer from various disadvantages. For example, the numerous wires that must pass from cards 14 to the various relays often result in large, bulky and complex wiring harnesses. Bulky and/or complex wiring harnesses, for example, increase manufacturing costs, make changes in the system more difficult, and can result in undesirable compromises in the overall system physical design in order to accommodate the wiring harnesses. In addition, it is often more difficult to implement redundancy with such a centralized control system, and the problems associated with maintenance and/or upgrades to the equipment tend to be complex and difficult.
The present invention is directed to improved control systems and methods utilizing inputs and outputs for purposes of controlling equipment (e.g., semiconductor process equipment), industrial machinery, processing lines, assembly lines and the like, and more particularly to input and output control systems and methods utilizing distributed input/output modules and integral interlocks. In preferred embodiments, a main controller module is provided, which desirably may be coupled to a host computer for controlling the equipment, processing line, assembly line, other environment, etc. The main controller includes a communications interface, such as for communicating with the host computer (or other interface for input and output of control commands, status or control information, etc.), and also includes at least first and second interlock controllers. The first and second interlock controllers communicate to a plurality of input/output (I/O) modules that are distributed in appropriate and desired locations in the equipment, line, environment, etc.
In preferred embodiments, each I/O module includes at least first and second slave controllers that communicate, respectively, with the first and second interlock controllers of the main controller, preferably over first and second communication paths. Each of the first and second slave controllers are coupled to a set of I/O drivers (and associated circuitry). In each I/O module, the inputs/outputs from each of the I/O drivers are logically combined, such as with an AND or other logical or other operation, to provide I/Os to the equipment, line, environment, etc. Preferably, each I/O module may be of a standard or identical design (preferably with a unique address or identifier), with each of the various inputs and outputs being programmable or configurable as inputs, outputs, analog, digital, etc.
In accordance with the present invention, a large number of inputs and outputs may be provided in the equipment, line or environment, with distributed I/O modules communicating with the main controller over a suitable bus, as opposed to a bulky wiring harness, etc. Redundant controllers in the main controller and the I/O modules, in accordance with preferred embodiments of the present invention, provide redundant, programmable, interlock control for the equipment, line or environment, etc. Standard-type I/O modules enable technicians to more readily repair and upgrade the equipment and the like.
Accordingly, it is an object of the present invention to provide distributed redundant control systems and methods, which are particularly suited for equipment such as semiconductor or other processing/fabrication equipment, and also may be configured for processing lines, assembly lines, building control, etc.
It is another object of the present invention to provide such control systems and methods that utilize redundant interlock control.
Finally, it is an object of the present invention to provide such control systems and methods that utilize a main controller and distributed I/O modules having redundant processors in order to provide redundant interlock control in a distributed, programmable and highly cost effective manner.